10 Popular: All Three Snaps

One of the reasons why Avengers: Infinity War ranks among the most popular films of the franchises so far was because of Thanos snapping his fingers at the end, wiping out half of the universe. It was a huge gamble to kill off many superheroes, but made it all the more emotional and hard-hitting when the film came out in 2018, with many people leaving cinema screens with tears in their eyes.

However, there were also snaps performed by the Hulk and Iron Man. For Hulk, his actions brought everybody back from the dead and allowed the green beast a moment in the spotlight after so many films on the fringes. For Tony Stark, it meant him being given one of the most heroic final moments in film history. All three snaps place further significance for all three characters and the Russo Brothers made each work in their own special way.

9 Popular: Blending Humour And Serious Tones

Thor's journey as a character takes us on to our next point. The Russo Brothers, in taking on Avengers: Infinity War and Avengers: Endgame, were signing up for some serious story-telling. For the first time, in those two films, the MCU was going to show us characters losing, heroes dying and individuals going to places and interacting with people they had never done so far before.

So their decision to keep things funny at times paid off, giving the film a unique and perfect balance. A bit of light relief was needed, particularly when some of the harder-hitting scenes took place. Thor led the way on this but there were also other characters who carried the funny mantle. Professor Hulk in Endgame was a blast, while Peter Parker's quips also went down a storm. To mix chaos and humor so well is a credit to the Russo brothers' ability to weave together such a compelling story.

8 Unpopular: No Deaths In Civil War

Fans still seem split on Captain America: Civil War over three years on from the film's release. And the decision not to kill anybody, in a movie of such gripping nature and sizeable magnitude, certainly divided fans when it hit screens back in 2016. After all, Tony Stark and Steve Rogers appear ready to fight to the death, only for them both to stop short of crossing the ultimate line. Given the sudden u-turn and decision to stop fighting, fans felt cheated. Particularly when the source material sees Cap die in an accident at his friend's hand. There was also the decision to leave War Machine paralyzed. Given how Don Cheadle played a marginal role in Avengers: Infinity War and Avengers: Endgame, his death could have been a bold decision that paid off and divided the team even further.

7 Popular: Evolving The Bucky And Cap Relationship

The Russo Brothers have been vital when evolving the relationship between Bucky Barnes and Steve Rogers. Both characters share an emotional bond throughout the movies, with Captain America: The Winter Soldier both hitting the emotional high notes. In Civil War, the magnitude of Steve's faith in his long-time friend reaches new levels when they join forces to take on Tony Stark, who wants Bucky dead for killing his father.

This could have backfired. After all, the decision to team Cap up with Bucky was what ultimately split the Avengers apart, something Tony references in Endgame. But it made for some of the MCU's most triumphant and emotional storytelling to date. Fans were on board with it as it also enhanced Cap's character and showed how, no matter what, he is willing to stick by those who have stuck by him.

6 Popular: Returning to Wakanda

After the success ofBlack Panther in 2017, people everywhere were going crazy for not just Chadwick Boseman's character, but the nation of Wakanda itself. The movie raked in a huge $242,155,680 on its opening weekend alone and, therefore, it was a popular decision to return to North Africa for the film's epic final act.

The beautiful scenery provided a fitting background to an epic conclusion, with Boseman's T'Challa leading the charge alongside Captain America. The film is where many of the heroes are dusted when Thanos survives a late attempt to stop him from Thor before clicking his fingers. There are also memorable scenes involving Okoye, Scarlet Witch, and Black Widow. We see Vision have the Mind Stone ripped from his head in brutal circumstances. Fans will no doubt relish returning once again for Black Panther 2.

5 Unpopular: Keeping Hulk Hidden Away

While Hulk's role in Avengers: Endgame has earned much praise, his role in the film's predecessor, Avengers: Infinity War, disappointed a fair few MCU fans. At the beginning of the movie, we see Bruce Banner engage Thanos in hand-to-hand combat, only to end up being brutally KO'd. Had it not been for some quick-thinking from Heimdall, he may even have been killed before the crux of the battle had even got underway.

And for the rest of the film, Banner's alter ego flatly refuses to emerge. Tony Stark labels it 'embarrassing' and, as the other Avengers challenge Thanos and his army, he has to resort to using the same Hulkbuster suit worn by the billionaire in Age of Ultron to take on the mad titan. Fans were disappointed that the superhero stayed as the amusing, albeit weaker, Banner rather than transform. Particularly when the Russos had included footage of the Hulk on Wakanda in the trailer.

4 Unpopular: Keeping Thor 'Fat'

As is bound to happen with a superhero, fans have plenty to say when it comes to how they should look. With Thor, there has been plenty of uproar regarding his appearances over the years, from the blonde eyebrows in his debut solo film to his shorter haircut in Thor: Ragnarok. Therefore, the Russos' decision to portray everyone's strongest hero as looking chubbier than usual, complete with a rather scraggly beard, was always going to be a hot topic of discussion in Endgame.

A film of that brilliance was going to have minor issues and the decision to keep the God of Thunder chunky throughout has sparked a semi-backlash from fans, who would prefer him to stay bulky and strong. The directors have explained how they wanted to show a weakness in Thor, while also making it clear that he was still worthy of fighting alongside the rest of the team. Despite that, however, many want him back to his old self should he appear in the future.

3 Popular: Turning To Familiar Faces

If you had seen the previous MCU films prior to Avengers: Endgame, you were treated to something pretty special when the film came out in April. Because the film provides major fan service by bringing characters from earlier chapters of the journey back into the fold, rewarding those who have stuck with them the whole time. And boy, do they the Russos make it work.

We see Hulk negotiate with the Ancient One for the Time Stone, Loki makes a cheeky escape with the Tesseract and Steve encounter Hydra enemies such as Crossbones all in New York alone. Old footage of Natalie Portman as Jane Foster is used to see her return to the series for the first time since 2013. And Tony Stark enjoys a final meeting with his father, Howard, in a charming scene that gives Iron Man closure. It all makes Endgame feel that more rewarding and the Russo brothers ensured it fit seamlessly into the story.

2 Popular: Fitting Finales

The common consensus among MCU fans is that Avengers: Endgame represents a job well done. It was always going to be difficult creating a blockbuster similar size-wise to Avengers: Infinity War, but the Russo brothers, like the heroes themselves, managed to pull it off. And for some of the characters, they were given tremendous send-offs in moments that cinema-goers will recall for years to come.

Black Widow sacrificed herself for Hawkeye to be with his family amid their hunt for the Soul Stone. That made sense, given how close she was to the Barton family, even once pressuring them into naming their third child after her. Captain America gets the ending he wanted all those years ago, finally having his dance with the love of his life, Peggy Carter. And Tony Stark, the same Tony Stark who had spent years trying to keep the universe safe for all these years, saves them all with a snap of his fingers. That looks to be their final outing, in a chronological sense at least. And it was some finale.

1 Developing The Character Of Iron Man

The Russo Brothers have helped make Robert Downey Jr's Iron Man the central face of the franchise, evolving his character in every single outing. For years, Tony Stark was a cocky billionaire with good intentions. But, now, he will be remembered as a hero complete in every sense of the word. By the time of his death, Stark has developed technology never seen before, settled down with Pepper Potts, had a child and done what was once unthinkable: relent. Stark gives in to his softer side in the latter stages of his story, acting as a mentor to Peter Parker and even putting his feud with Captain America behind him. Audiences see him as more than a billionaire. They see him as a father, as a guide, as a leader capable of succeeding even if it means failing first. Stark goes on a rollercoaster in three of the four films the Russo directed and comes out looking greater on the other side.